36 MICROSCOPIC OBJECTS. 



of the Cimex ; one fC. HirundinisJ is met with in the 

 nests of martins; another fC. ColumbariusJ infests pigeons; 

 and the third (C. Pipistrelli) is a parasite of the PipistrelU 

 Bat. These three are figured by the Rev. L. Jenyns, in 

 the Annals of Natural History, vol. iii. 



Centipede. — ^This creature is well suited for shallow 

 magnifiers, and becomes a permanent subject when 

 mounted in Canada balsam. The arrangement of its 

 respiratory system is worthy of minute examination. 

 When alive it may be taken at night, as it emits a flash of 

 light when suddenly approached. 



Coral. — The mode of deposition of carbonate of lime 

 by these Zoophytes can be readily seen by examination of 

 thin sections ; these should be cut in two directions — one 

 transverse and the other parallel to the axis. — Magnify- 

 ing power 50 diameters. 



Disc, Foot. — This object, which is obtained from the 

 leg of the male Dytiscus, is part of the suction appara- 

 tus by which that aquatic beetle seizes the female. When 

 mounted in balsam as a transparent object, the strong 

 radial fibres are distinctly seen. 



Dorsal Vessel of the Larva of the Ephemera — ^is a very 

 delicate preparation. It is supposed by some, from its 

 pulsatory movements, to perform the function of a heart. 

 The air tubes which surround it are composed of a mem- 

 brane lined by a spiral fibre. 



Curculio. — Many of the English species of this genus 

 of beetles, when mounted entire, are magnificent sub- 

 jects for the opaque microscope. The specimens should 



